Around 950 AD Gísli Súrsson and his family decide to leave Norway and move to Iceland. Approximately ten years later, Gísli kills his brother-in-law, Thorgrim, and is outlawed and forced to stay on the run for thirteen years. The saga begins with two brothers, Gisli and Thorkel, and their brothers-in-law, Vestein and Thorgrim joining together in a ceremony that will signify each other's loyalty to one another. However, this ceremony, known as the traditional sworn oath of brotherhood, was not completed because Thorgrim retracts his obligation to Vestein, which in turn causes Gisli to negate his bond with Thorgrim. From this moment on the characters’ actions seem to be controlled completely by fate as they head down a tragic path.
A chain of dreadful events is set into motion when Thorkel catches his wife, Asgerd, and Aud, Gisli’s wife, gossiping about loves they had before they were married. When Asgerd reveals that her previous lover was Aud's brother, Vestein, Thorkel is infuriated and decides to move away from the farm that he and Gisli shared. Thorkel and Asgerd move onto a nearby farm that is owned by Thorgrim. Upon his arrival, Thorkel joins with Thorgrim to discuss various things, perhaps even planning Vestein’s murder, however nothing is certain. Soon after Thorkel moves in with Thorgrim, Vestein comes back to Gisli's farm to visit with the family. Aud explains to Gisli what her and Asgerd were gossiping about and how Thorkel overheard their conversation. Gisli attempts to warn Vestein not to come back into the village because it is not safe for him. Unfortunately, Vestein is not warned in time and successfully arrives in the village. Soon after, he is murdered one night while sleeping at Gisli’s house. Gisli rushes into the house and grabs the spear out of Vestein’s chest, signifying that he will take vengeance for Vestein’s murder. Although the identity of the intruder is never revealed, Gisli is haunted by dreams which convince him that Thorgrim is the murderer. In these dreams there is a symbolic good and evil woman which seem to represent the choice Gisli must eventually make.
Now, in order to avenge the death of Vestein, a man to whom he is bound, Gisli murders Thorgrim and escapes into the night without being discovered. However, Thordis, Gisli’s widowed sister suspects that it is Gisli that must have murdered her husband, therefore, he must be outlawed. Once Gisli is outlawed he constantly runs from a group of men who wish to find and murder him. This task proves to be more difficult than perceived, as they are unable to locate Gisli in his various hiding places. While Gisli is on the run, Vestein's two sons decide to seek out their own vengeance for their father's murder. The two boys murder Thorkel, but Gisli chooses not to hunt them down because they are Aud's relatives.
Aud, Gisli’s wife, remains loyal throughout the saga and refuses to divulge the location of her husband, even when offered three hundred silver pieces for her knowledge. Gisli's dreams continue to plague him, and eventually he is not able to run from his problems or the people who are hunting him. After Gisli is discovered, Aud fights side-by-side with her husband until he is killed in a final, strenuous battle. Even after Gisli is dead, he is still honoured and respected for being a loyal and honest man. The saga notes that his final blow was just as strong as his first. Once Gisli faces his death, Thordis experiences remorse for his murder and stabs Eyjolf in the leg. After Bork wrenches the sword out of her hand and attempts to calm the group, Thordis declares herself divorced from Bork and leaves the house. Aud converts to the Christian faith and takes a pilgrimage to Rome, never to return back to Iceland.
| Character | Information |
|---|---|
| Gisli | The main character of the saga that decides to seek out vengeance for the murder of Vestein. He kills Thorgrim because he believes he is the murderer. Gisli is outlawed by his own sister. |
| Aud | Gisli’s wife and Vestein's sister. She stays loyal to her husband even when faced with her own death. |
| Thorgrim | Thordis' husband and the suspected murderer of Vestein. Refused to make the oath with Vestein because he felt it would cause him more trouble and stress. |
| Thorkel | Gisli’s brother who lives on a farm with Thorgrim. Thorkel chooses to help Gisli but only to a certain extent. The two sons of Vestein, in search of vegence, kill Thorkel. |
| Asgerd | Wife of Thorkel. She starts a long chain of tragic events when Thorkel overhears her confessing her love for Vestein. |
| Vestein | He is Gisli’s brother-in-law and best friend who is murdered in his sleep. |
| Eyjolf | Leader of the group of men who hunt after Gisli. |
| Thordis | Wife to Thorgrim and sister to Gisli. After Thorgrim's murder she remarries to Bork and urges him to avenge the death of his brother Thorgrim by killing Gisli. |
| Bork | Thordis’ second husband and Thorgrim’s brother. He decides to chase after Gisli in pursuit of vengeance fo Thorgrim's death. |
| Helgi | One of Eyjolf's Men. |